Watch-crystal.



L. E. F. WACHTER.

WATCH CRYSTAL.

ATION FILED DEC-24,1817.

APPLIC Patented Dec. 17, 1918.

KV/fi? e 55 e s,

r w W m y .3 F m E LOUIS E. F. WACHTER, OF NEW YORK, N. Y.

WATCH-CRYSTAL.

Specification of Letters Patent.

Patented Dec. 17, 1918.

Application filed December 24, 1917. Serial No. 208,592.

To all whom. it may concern:

Be it known that I, LOUIS E. F. WACHTER, a citizenof the United. States, residing in the city, county, and State of New York, have invented certain new and useful Improvements in Watch-Crystals, of which the following is a specification, reference being had to the accompanying drawings, illus-- trative of one particular embodiment of my invention.

This invention relates to crystals for watches, by which-ismeant a suitable transparentclosure for watches or like articles, whieh may be Blade of various materials. In particular, aniong the objects are to produce a crystalwhichis supported by a rim engaging into the material of the crystal while permitting the crystal to expand and contract and at the same time hol'ding it secnreiy JErfcjinv detachment.

The "demand f r a amps- P113516 composition disk forwatche's,- clocks orllike articles, makes it necessary to produce one whichwill not fall from its inclosing frame due to the contraction of such composition. Efforts have been made to overcome this objection by holding a composition disk tight in its fastenings, by crimping the edges of the disk between metal walls, and in so .doing it resulted in the disk warping, splitting or breaking from its fastenings due to the contraction of the material, and generally the influence of atmospheric conditions or seasoning.

My invention overcomes all of these difliculties, and it reduces the cost of manufacture and makes it possible to put such crystals on any existing watches or like articles, without otherwise making any change in the watch case. It may be said that one of the main objects is to allow for movement of the transparent disk to accommodate expansion and contraction in its support, by having a rim engaging into the body of the crystal and between the border or planes of the inner and outer face of the crystal. In some forms it will be seen that the rim engages between the planes of the upper and lower surfaces of tural means on the engaging portion of said rim to cooperate with the edge wall or shoulder of the crystal, which prevents detachment of the crystal from its support when contraction takes place. The dimensions of the disk, having structhe interengaging edges of the rim, and the thickness may be made to correspond or suit the size and thickness of the disk.

In the particular embodiments shown in the accompanying drawings and hereinafter specifically described Figure l is a view of the outer face of a crystal.

Fig. 2 is a diametrical section of the crystalin Fig. 1.

, Fig. 3 1s a diametrical section of a crystal with slightly modified detail of rim connection.

Fig. 4 is a view of the face of such a crystill-with the main disk of slightly modified construction. V

Fig. 5 is a diametrical section of Fig. 4:.

Fig 6 is a diametrical section of a crystal. with-a modification in the detail of rim attachme nt.

Fig. 7 is a plan View of the of a crystal showing a modification in a detail of the :interengaging rim.

The crystalas shown consists of the con tral transparent of pliable composition such. as celluloid or other material, a rim B, which, in my preferred form, is of metal,'- and has the peripheral edge C suitable for interconnection with the ordinary engaging groove of a bezel. Inwardly projecting on B' is the flange D between -the outer lip a of the disk A and theinner lip a.

As shown in Fig. 3 the flange D engages the outer lip a of the disk A, and the annular member E is cemented to the inner side of the rim of the disk A and engages the inner side of the flange D.

In Fig. 4c, the transparent disk F comprises a wire mesh F, with an outer and inner transparent coating ff, and the wire mesh F merges at its edge with or is attached to a peripheral rim G, having the outer lip a andthe inner lip a of the disk bearing upon it, while the rim G terminates in a peripheral edge g, suitable for attachment to a groove in the article to which the crystal is to be applied.

In Fig. 6, the disk H has an edge lip h and a projecting ridge h. As shown on one side. this lip permits the insertion of a peripheral rim J, and on the other side of the section is shown the ridge h of the disk material turned or pressed over into engagement or portion A, .which may be bearing with the under side of the rim J, thereby forming outer and inner bearings for the rim.

As shown in Fig. 7, the rim J, or it may be a rim like B, has its radially inward edge 7' serrated, or with projections, which in the manufacture may be forced into the material of the disk, or when formed as in Fig. 6, the material of the disk will be pressed over these projections. In this construction any contraction of the material of the transparent disk which would cause it to shrink away inwardly with respect to the rim, would still assure the engagement of the projections jso as to prevent circular movement or relative rotation of the rim and disk.

It will thus be seen that should the central transparent disk shrink, it would still have a bearing on the inside and outside of the flange D of the rim B, or on the inner edge of the rim G or rim J, which bearing would continue to hold the central disk against displacement inwardly or outwardly, and, in other words, prevent the transparent disk from falling out of its securing members. With any expansion after contraction,

the holding of the disk will still be secure.

In spite of any contraction or expansion of the transparent disk, the rim in form B, G, J or otherwise, which in my preferred form is of metal, but may be made of other material, will always maintain substantially uniform diameter, and can therefore be made of fixed sizes to properly engage the regular sizes of watch bezel or the like, and be applied to the same or detached from the same in a manner usual in the ordinary glass crystal.

As shown in Fig. 3, the cemented rim E may facilitate the manufacture, producing the same results as the finished construction shown in Fig. 2. The constructions in Figs.

4 and 5, involve simply a modification of the material of the transparent disk and such detail modification that might be necessary in the manufacture to secure the rim under the circumstances. The overhanging extent of the lips, as shown in Figs. 2 and 3, are suitably proportioned to meet the particular conditions of size and material involved.

While my invention may be modified in various-ways in construction and material, from that particularly herein shown and described, what I claim anddesire to secure by Letters Patent is:

1. In a crystal for a watch or like article, a transparent disk, a supporting rim embedded in the edge of said disk between the upper and lower surface planes thereof, a retaining edge on said rim for engagement with the bezel.

2. In a watch crystal, a main transparent disk carrying between its borders a circumferential plate or rim extending beyond the diameter of the transparent disk.

Signed at New York, this 22nd day of December, 1917 LOUIS E. F. WACHTER.

Witnesses:

HERMANN F. CUN'rz, H. MUCHMORE. 

